METHOD FOR WASHING AROMATIC POLYETHER BY USING CARBON DIOXIDE

摘要

PROBLEM TO BE SOLVED: To provide a washing method by which an alkali metal included in an aromatic polyether is sufficiently removed. SOLUTION: The aromatic polyether is washed by using an aqueous medium containing carbon dioxide. Carbon dioxide gas and dry ice can be used as the carbon dioxide. Water or a mixed solvent of the water with an organic solvent can be used as the aqueous medium. The pH of the aqueous medium is usually 4-5.